Currently have version 38 on my P3. The site mentions that updates are still available until January 2018 but makes no mention as to how to go about this. I guess more importantly, is there any real benefit to doing this even if it is possible?

I don't plan on updating any of my provaris. A) I am not good at updates and I'd hate to do something to make my mod non-functional and without support really after that (though I guess I could send it to that repair guy) but also mine are working fine and I use lower wattages anyway, so I'm not stressed about it.

To me, I see more disadvantages than benefits, but I'm sure that others might feel differently and also be able to help you get it done, or at least tell you what the outcome should be...